WO2011013510A1

WO2011013510A1 - Multi-optical axis photoelectric sensor

Info

Publication number: WO2011013510A1
Application number: PCT/JP2010/061852
Authority: WO
Inventors: 亮小澤; 孝義高原; 一功尾▲さこ▼
Original assignee: オムロン株式会社
Priority date: 2009-07-30
Filing date: 2010-07-13
Publication date: 2011-02-03
Also published as: JPWO2011013510A1; JP5131386B2

Abstract

A multi-optical axis optical unit is provided in each of the casings of a projector and an optical receiver of a multi-optical axis photoelectric sensor. Each multi-optical axis optical unit includes a shield member (support frame 4) where a plurality of flexible wall portions (41A, 41B) are arrayed on the side edges of a plate base (42), a plurality of fixing holders (5) which have insulation properties and are fitted between the wall portions (41A, 41B) opposed to each other by sandwiching the base (42), a plurality of optical modules (3) supported by the fixing holders (5), and a strip-shaped conductive member (flat cable 6) held between each fixing holder (5) and each optical module (3) on the upper surface of the base (42) of the shield member and electrically connected to each optical module (3). Wall portions (41A, 41B) in positions where a fixing holder (5) and optical module (3) are arranged hold the optical module (3) cooperatively with the fixing holder (5). On the other hand, wall portions (41A, 41B) in positions where no fixing holder (5) and optical module (3) are arranged are bent inward to shield the conductive member.

Description

Multi-optical axis photoelectric sensor

The present invention forms a two-dimensional detection area by a plurality of optical axes by arranging a light projector and a light receiver, in which a plurality of optical modules are incorporated, with the light emitting surface and the light receiving surface facing each other. Multi-optical axis photoelectric sensor.

The applicant has recently accommodated each of the light emitting element and the light receiving element in an independent optical module, and has made it possible to change the number and spacing of the optical modules according to the environment and purpose in which the sensor is installed. A multi-optical axis photoelectric sensor was developed (see Patent Document 1).

FIG. 9 shows the configuration of the optical module 200 disclosed in Patent Document 1 by an exploded perspective view (1) and a partially broken perspective view (2).
In this optical module 200, an optical IC chip 205 including an optical element (light emitting element or light receiving element), a shield member 204, a trap 202, and a lens member 201 are integrally provided in a resin holder 203 having a light guide 206. It is. The trap 202 and the lens member 201 are fixed at the upper end position of the light guide 206, and the optical IC chip 205 is attached to the bottom of the holder 203 with the shield member 204 interposed therebetween.
The lens member 201 is provided with a projecting piece 201 a for positioning, and a hole 204 a communicating with the light guide 206 is formed at the center of the shield member 204.

From the end edges of the optical IC chip 205, four pressure contact type lead pins 205a each having a bifurcated tip are protruded. 9 (1) and 9 (2), although only the lead pins 205a at one end are shown, these lead pins 205a and the lead pins 205a at the other end not shown are in the longitudinal direction of the chip 205. Alternately located along the.

FIG. 10 shows the appearance of a multi-optical axis optical unit using the optical module 200 described above.
This multi-optical axis optical unit includes a support frame 250 in which a plurality of wall portions 250a are arranged at both end edges, a plurality of fixing holders 230, the same number of optical modules 200 as the fixing holders 230, and eight signals. It is comprised by the flat cable 220 which integrated the wire. At the time of assembly, the respective fixing holders 230 are respectively fitted and fixed between the wall portions 250a and 250a opposed in the width direction of the support frame 250, and the flat cables 220 are supported thereon in the arranging direction of the respective signal lines. In accordance with the width direction of the frame 250, the optical module 200 is fitted into each fixing holder 230. The optical module 200 is held by the standing portions 230a and 230a at both ends of the fixing holder 230 and the wall portions 250a and 250a that support them.

In addition, the lead pins 205a protruding from the optical IC chip 205 are respectively inserted into the flat cable 220 by the pressing force when the optical module 200 is inserted, and the signal lines are sandwiched between the central slits of the lead pins 205a. . Thus, the lead pins 205a are connected to the signal lines in a one-to-one relationship.

According to the above-described assembly structure, the number of optical axes of the multi-optical axis optical unit and the distance between the optical axes can be easily changed by changing the length of the support frame 250 and the distance between the optical modules 230. .

The support frame 250 is made of metal and holds the optical modules 200 and the flat cable 220, and also functions as a shield member for preventing electromagnetic noise from the outside. However, since the optical modules 200 are spaced apart, the upper surface of the flat cable 220 is exposed between the optical modules 200, and this exposed portion may be affected by an external electromagnetic wave. . Therefore, another shield member 260 is put on the multi-optical axis optical unit from above to protect the upper surface of the flat cable 220 from electromagnetic noise.

A light passing hole 260d is formed at a position corresponding to the optical module 200 of the shield member 260, and locking pieces 260c to the holder 203 of the optical module 200 are provided at both ends. At both ends of the portion that does not correspond to the optical module 200, shielding portions 260b that slope obliquely downward are provided in a row.

Patent No. 3865074

In the multi-optical axis optical unit having the above configuration, the lower end portion of the shielding portion 260b of the upper shielding member 260 and the upper end portion of the wall portion 250a of the support frame 250 are joined by soldering to form a pair of upper and lower shielding members 250. , 260 are physically and electrically connected. However, in such a configuration, the longer the sensor, the more labor required for assembly and the longer the working time. In addition, if the accuracy of the soldering is poor, the shield member 260 may not be fixed with sufficient strength, and the shielding function may also be deteriorated.

Furthermore, in the upper shield member 260, the positions where the openings 260d and the shields 260b need to be formed correspond to the structure of the multi-optical axis optical unit, so the arrangement intervals of the optical modules 200 may be set plurally. In this case, the shield member 260 must be prepared according to each configuration.

In place of the method of covering the entire upper part of the multi-optical axis optical unit, a method of attaching the shield member only to the portion where the flat cable is exposed is also proposed (see FIG. 22 of Patent Document 1). However, even with this method, it is necessary to solder the upper shield member to the support frame 250 or to use a shield member having a width corresponding to the arrangement distance of the optical module 250, so the above-mentioned problems can not be solved. .

The present invention focuses on the above problems, and has an object to eliminate the need to cover a shield member from the top and to ensure a sufficient shield function by a simple method.

According to the present invention, a plurality of optical modules including optical elements and their processing circuits are projected in each housing of a light projector and a light receiver having a frame body having a window for forming light on the front surface. The present invention is applied to a multi-optical axis photoelectric sensor having a configuration in which the light surface or the light receiving surface is disposed along the longitudinal direction in a state of facing the window portion. Inside each case, a shield member in which a plurality of flexible wall portions are arranged in a row on the side edge of a plate-like base has insulation properties, and the wall portions facing each other across the base A plurality of fixing holders to be fitted between each other, a plurality of optical modules respectively supported by the respective fixing holders, and a holding member held between the respective fixing holders and the respective optical modules on the upper surface of the base of the shield member And a multi-optical axis photoelectric sensor having a strip-shaped conductive member electrically connected to each optical module. Further, the wall where the fixing holder and the optical module are arranged cooperates with the fixing holder to fix and support the optical module, while the wall where the fixing holder and the optical module are not arranged Are bent inward to shield the strip-shaped conductive member.

According to the above configuration, each of the optical modules is supported by the fixing holder disposed at an appropriate position of the shield member and the wall portion in a cooperative relationship with the holder, and the optical module row and the fixing holder A conductive state (a flat cable, a flexible substrate, and the like) in a strip-like conductive member (flat cable, flexible substrate, etc.) sandwiched between the columns is established. The location where the fixing holder and the optical module are not provided is shielded by the inwardly bent wall.

Since the electromagnetic noise can be prevented from acting on the exposed upper surface of the strip-like conductive member by bending the wall in this manner to approach the strip-like conductive member, it is not necessary to cover another shield member from above. . Therefore, the number of parts can be reduced, and the work for joining the shield members becomes unnecessary. Further, even when the distance between the optical modules is changed, it can be easily coped with by inward bending the wall portion of the portion where the strip-like conductive member is exposed.

In a preferred aspect of the above optical member, the wall portions are arranged at equal heights on both side edges of the base portion, and when the two opposing wall portions are bent inward on both sides of the base portion, these wall portions Is configured to shield the entire width of the strip-shaped conductive member. According to such a configuration, at the position where the optical module is disposed, the optical module can be stably held on both sides, and a sufficient shielding function is exhibited with respect to the portion where the strip-like conductive member is exposed. be able to.

According to the present invention, it is not necessary to perform complicated work, and a shielding function for the multi-optical axis optical unit can be secured, and the number of parts can be reduced. Therefore, the cost can be reduced, and the multi-optical axis optical unit can be completed in a short time. In addition, it is possible to easily cope with the case of manufacturing sensors having various numbers of optical axes and intervals between the optical axes.

It is a perspective view showing the appearance of a multi-optical axis photoelectric sensor. It is a perspective view which shows the structure of the multi-optical axis optical unit accommodated in a light projector and a light receiver. It is a front view of a multi-optical axis optical unit. It is a side view of a multi-optical axis optical unit. It is a top view of a multi-optical axis optical unit. It is a perspective view which shows the structure of an optical module. It is the perspective view and top view which show the structure of a support frame. It is a perspective view which shows the structure of the holder for fixing. It is the disassembled perspective view which shows the structure of the optical module used for the conventional multi-optical axis optical unit, and the perspective view which notched one part. It is a perspective view which shows the structure of the conventional multi-optical axis optical unit.

FIG. 1 shows the appearance of a multi-optical axis photoelectric sensor to which the present invention is applied.
The light projector 1 and the light receiver 2 of this multi-optical axis photoelectric sensor are each provided with a plurality of optical elements (the light emitting element 10 in the light projector 1 and the light receiving element 20 in the light receiver 2) and control inside the housing 100 having a long shape. A substrate (not shown) is accommodated. From the lower end portion of each case 100, a cord 101 in which various signal lines are put together is drawn out. A second cord 102 for extension is further connected to the cord 101.

At the front of each case 100, a window 103 for passing light is formed. The light emitting element 10 and the light receiving element 20 are arranged to align along the longitudinal direction of the housing 100 with the light emitting surface and the light receiving surface facing the window portion 103. The light projector 1 and the light receiver 2 are disposed to face each other at a predetermined interval so that the light emitting elements 10 and the light receiving elements 20 face each other in a one-to-one relationship. As a result, for each combination of the light emitting element 10 and the light receiving element 20, the positions and directions of these optical axes are aligned.

2, 3, 4, and 5 respectively show the front side (light emitting surface or light receiving surface) of the configuration of the multi-optical axis optical unit disposed in the housing 100 of the light projector 1 and the light receiver 2 described above. It shows by the perspective view, the front view, the side view, and the top view which were turned up. 2, 4 and 5 show only the configuration corresponding to the first two optical axes, but the same configuration as shown in each drawing is applied to the subsequent optical axes.

In this embodiment, each optical element (the light emitting element 10 in the light projector 1 and the light receiving element 20 in the light receiver 2) is accommodated in an independent optical module 3 as in Patent Document 1 and a plurality of optical modules 3 Are fixedly arranged at desired positions along the length direction of the support frame 4. A fixing holder 5 is used to fix each optical module 3. Further, the flat cable 6 is sandwiched between the row of the optical modules 3 and the row of the fixing holders 5 so that the optical modules 3 are conducted to the respective signal lines 61 to 68 of the flat cable 6.

FIG. 6 shows the configuration of the optical module 3. This optical module 3 has a shape slightly different from that of the conventional example shown in FIG. 9, but the substantial configuration and function are the same. In the figure, reference numeral 31 denotes a holder having a light guide, and reference numeral 32 denotes a lens member 32 disposed on the upper side of the light guide. Further, at the bottom of the holder 31, a shield member 37 and an optical IC chip 35 having a plurality of lead pins 36 are mounted.

The holder 31 is a molded article made of resin, and the portion surrounding the lens member 32 is formed wide. At the corners (a total of four places) of the wide parts, rod-like locking pieces 33 having claws 34 at their tips are integrally provided with the length direction facing downward. Further, a second rod-like locking piece 38 not having a claw portion is provided integrally integrally with the length direction facing downward, slightly inside the locking pieces 33, respectively.

FIG. 7 shows the structure of the support frame 4. The support frame 4 of this embodiment has a shape in which a plurality of wall portions 41A and 41B are integrally lined at both ends of a plate-like base 42 having a longitudinal shape, and is made of flexible metal (for example, phosphorus It is formed by a molding process using bronze or aluminum). In the molding step, a frame having a considerable length is formed, and the frame cut out in accordance with the length of the housing 100 is the support frame 4.
In addition, the support frame 4 is electrically connected to a shield wire (not shown). Thus, in addition to the function of holding the optical module 3 and the flat cable 6, the support frame 4 is set to have a function as a shield member.

The wall portions 41A and 41B of the support frame 4 are disposed opposite to each other with the base 42 interposed therebetween. Each of the wall portions 41A and 41B has a width corresponding to one optical module 3, and the height is approximately half the width of the base 42. In each of the wall portions 41A and 41B, the lower wall width is formed wide, and the step portion 44 is formed at both end edges of the portion where the wall width changes. Further, on the inner surface of the wall portions 41A and 41B, a groove 48 along the width direction is provided at a position slightly above the step portion.

A pair of

holes

45 and 45 are formed in the connection position of each wall 41A and the base 42 provided on one side edge of the support frame 4 respectively. One wide hole 47 is formed at the connection position between each wall 41B and the base 42 provided on the other side edge of the support frame 4. Further, a pair of

holes

46, 46 is formed on the groove 48 in any of the wall portions 41A, 41B.
Further, on both side edges of the base portion 41, notch holes 49 are formed respectively connected to the gaps between the wall portions.

The wall portions 41A and 41B of the support frame 4 can be bent inward at the position of the groove 48. Further, by bending the opposing wall portions 41A and 41B with the base portion 42 interposed therebetween, the entire width of the base portion 42 can be covered with the wall portions 41A and 41B.

8 (1) and 8 (2) show the configuration of the fixing holder 5. FIG. The fixing holder 5 has a pair of rising

portions

50A and 50B connected to both side edges of the base 52 on the surface of which three corrugated plates 59a, 59b and 59c are formed. It is comprised by integral molding with resin. In addition, 502 in the figure is a hole which arose when it was pulled out from a jig | tool after shaping | molding.

Each of the rising

portions

50A and 50B has a configuration in which the columnar bodies 51 are continuously provided on both sides of the U-shaped main portion 58, respectively. At the upper end position of the main portion 58 of each of the rising

portions

50A and 50B, a pair of locking pieces 56 are provided so as to protrude on both sides of the notch groove 58a. A pair of locking pieces 55 project from the lower end edge of the main portion 58 of the rising portion 50A, and a wide locking piece 57 protrudes from the lower edge of the main portion 58 of the rising portion 50B. These locking

pieces

55, 57 are bent below the lower surface of the base 52, respectively, and there is a gap between the bent portion and the lower surface of the base 52 according to the thickness of the base 42 of the support frame 4. It is set.

Each columnar body 51 is formed higher than the main portion 58, and a step is formed on the outer wall surface by forming the upper portion thick. The step is set to substantially the same height as the locking piece 56 of the main portion 58. Further, the entire length of each columnar body 51 corresponds to the length of the locking piece 38 of the optical module 3, and the length of the thick portion 54 of each columnar body 51 corresponds to the claw portion of the locking piece 33 of the optical module 3 It corresponds to the length except 34.

Four L-shaped protrusions 53 are provided on the upper surface of the base 52. The longer projecting pieces of the respective projecting portions 53 are parallel to the wall surfaces of the columnar bodies 51 of the respective rising

portions

50A and 50B, and face each other with an interval corresponding to the thickness of the locking piece 38 of the optical module 3 .

Each corrugated plate 59a, 59b, 59c is provided with a number (eight) of grooves corresponding to the flat cable 6, respectively. Further, a projecting piece 501 for positioning the flat cable 6 is provided on the central long wave plate 59a.

The assembly structure of the multi-optical axis optical unit will be described below with reference to FIGS.
In the fixing holder 5, the locking

pieces

55, 55 on the side of the rising portion 50A of the fixing holder 5 are holes 45 in the wall portion 41A with respect to the wall portions 41A, 41B opposite to each other with the base portion 42 of the support frame 4 interposed therebetween. 45, the locking pieces 57 on the side of the rising portion 50B of the fixing holder 5 engage with the holes 47 of the wall portion 41B, and the locking pieces 56 of the main portion 58 of the rising

portions

50A and 50B are walls By entering the holes 46 of the portions 41A and 41B, the wall portions 41A and 41B are held. In addition, since the base 42 of the support frame 4 is sandwiched between the end portions of the locking

pieces

55, 55, and 57 and the lower surface of the base 52, removal of the fixing holder 5 is restricted. Further, at this time, the thick portions 54 of the columnar bodies 51 of the rising

portions

50A and 50B are located above the step portions 44 of the corresponding wall portions 41A and 41B.

The flat cable 6 has a configuration in which eight signal lines 61 to 68 arranged in parallel are embedded in a resin. In the flat cable 6, holes (not shown) are formed at regular intervals in the line in which the signal line corresponding to the projecting piece 501 of the base 52 of the fixing holder 5 is embedded. By fitting this hole into the projection 501, the flat cable 6 is fixed in a state where each signal line is aligned with the corresponding groove of each of the wave plates 59a, 59b, 59c.

In addition, the hole of the flat cable 6 is provided in the position of the signal wire | line which needs to cut off the electrical connection between optical axes. The flat cable 6 is bent downward at the front end edge of the support frame 4 and connected to the connector 60.

Between the locking

pieces

33, 38 of the holder 31 of the optical module 3, the pillars 51 at both ends of each of the rising

portions

50A, 50B, respectively, with respect to the fixing holder 5 in the state of supporting the flat cable 6 as described above. The optical module 3 is fixedly held by positioning the optical module 3 so as to be in the gap between the two and applying pressure to the optical module 3. Specifically, the locking piece 33 of the holder 31 of the optical module 3 is engaged with the thick portion 54 of the columnar body 51 at the upper position of each step portion 44 of the wall portions 41A and 41B, and the fixing holder The locking piece 38 enters the gap between the protrusion 53 provided on the base portion 52 of the fifth member 5 and the columnar body 51. At this time, the claws 34 of the locking pieces 33 engage with the lower surface of the thick portion 54, and the locking

pieces

33, 33 positioned on the

step portions

44, 44 at both ends of the wall portions 41A, 41B. With the wall portion 41A or 41B sandwiched in between, removal of the holder 31 is restricted.

When the optical module 3 is pressed, the lead pins 36 of the optical IC chip 35 attached to the bottom of the holder 31 break the coating of the flat cable 6 and are inserted inside, and the lead pins and the signal lines 61 to 68 are paired It becomes conductive in one relationship.

In this embodiment, the fixing holder 5 and the optical module 3 are disposed at intervals of one wall along the length direction of the support frame 4. The wall portions 41A and 41B at positions where the fixing holder 5 and the optical module 3 are not disposed are bent inward at the position of the groove 48 as shown in FIGS. As a result, the exposed portion of the flat cable 6 between the optical modules 3 is shielded over the entire width except the portion near the adjacent optical module 3. Further, since the strength of the shield for the flat cable 6 is enhanced by bending the wall portions 41A and 41B close to the upper surface of the flat cable 6, it goes without saying that the portions shielded by the wall portions 41A and 41B are of course It is also possible to protect electromagnetic noise to a portion not covered by the wall portions 41A and 41B.

According to the above configuration, the lower surface and the upper surface of the flat cable 6 can be protected by a single shield member (support frame 4). In addition, since the exposed portion of the cable 6 can be shielded only by bending the wall portions 41A and 41B in a position where the optical axis module 3 is not disposed inward, the arrangement interval of the optical modules 3 is changed. , It is not necessary to change the component parts and can be easily coped with. Therefore, even when manufacturing a long sensor, the work for setting the shield does not require much time and the number of parts for the shield can be reduced to one, so that the cost and labor can be significantly reduced.

Further, in the above embodiment, each optical module 3 is disposed at an interval of one wall along the length direction, but the present invention is not limited to this. Each optical module 3 may be disposed open. Further, the intervals between the optical modules 3 are not limited to equal intervals, and there are a portion in which the optical modules 3 are densely arranged and a portion in which the optical modules 3 are sparsely arranged depending on the use environment of the sensor. It is also good.
In any arrangement, the upper surface of the flat cable 6 is exposed by bending the wall portions 41A and 41B in which the fixing holder 5 and the optical module 3 are not disposed inward as in the above embodiment. Since electromagnetic noise to a certain place can be protected, it is possible to easily cope with a change in the configuration of the multi-optical axis optical unit.

Moreover, according to the configuration of the support frame 4 described above, the optical modules 3 can be disposed without spacing, that is, the optical modules 3 can be disposed to the adjacent wall portions in the length direction. It is. Also in this arrangement, the wall portions 41A and 41B in which the fixing holder 5 and the optical module 3 are not arranged are directed inward, unless the optical module 3 is arranged on all the wall portions 41A and 41B of the support frame 4 By bending, the exposed portion of the top surface of the flat cable 6 can be protected from electromagnetic noise.

Furthermore, in the above embodiment, the flat cables 6 are shielded by equalizing the heights of the wall portions 41A and 41B of both end edges of the support frame 4 and bending the both wall portions 41A and 41B. The wall of one side may be made higher than the other, and only the higher wall may be bent to shield the flat cable 6.

In the above embodiment, each optical module 3 is connected to the flat cable 6 through a pressure contact type lead pin, but instead of the flat cable 6, a flexible substrate on which each signal line is wired is used It is also possible. In this case, in order to connect the optical module 3 to the signal line, a plurality of bump electrodes may be provided on the bottom surface of the optical IC chip 35 instead of the lead pin 36 and each bump electrode may be soldered to the signal line.

Further, in the above embodiment, the optical modules 3 for one optical axis are spaced apart, but the present invention is not limited to this, and the above-described optical modules may be arranged in a row in which a plurality of optical elements are accommodated. By applying the same configuration as that of the embodiment, it is possible to protect the wiring between each optical module from electromagnetic noise with one shield member. Also, in this case, the width of each wall of the support frame is sized so that a plurality of walls are arranged on both sides of the optical module, and the optical modules are arranged with one or more walls apart. be able to.

Reference Signs List 1 light emitter 2 light receiver 3 optical module 4 support frame 5 fixing holder 6 flat cable 10 light emitting element 20 light receiving element 31

holder

33, 38 locking piece 41A, 41B wall 42

base

45, 46, 47

hole

50A, 50B standing portion 51 columnar body 52 base 53 protrusion 54

thick portion

55, 56, 57 locking piece

Claims

A plurality of optical modules including an optical element and its processing circuit are provided in the housing of a light projector and a light receiver, each of which has a frame body having a window portion for transmitting light on the front surface as a housing A multi-optical axis photoelectric sensor disposed along a longitudinal direction with a surface facing the window portion, comprising:
In the inside of the housing, a shielding member in which a plurality of flexible wall portions are arranged in a row on the side edge of a plate-like base has insulating properties, and is a wall portion facing the sandwiching the base Between a plurality of fixing holders fitted between the plurality of optical modules supported respectively by the respective fixing holders, and between the respective fixing holders and the respective optical modules on the upper surface of the base of the shield member A multi-optical axis optical unit having a strip-shaped conductive member electrically connected to each of the optical modules,
The wall where the fixing holder and the optical module are arranged cooperates with the fixing holder to hold the optical module, while the wall where the fixing holder and the optical module are not arranged is inside A multi-optical axis photoelectric sensor which is bent in a direction to shield the strip-like conductive member.
The wall portions are arranged at equal heights on both side edges of the base portion, and when the two wall portions facing each other across the base portion are bent inward, the wall portions of the strip-shaped conductive member Multi-optical axis photoelectric sensor with full width shielded.